Experimental investigation of fiber laser welding of automotive aluminum 6016 to galvanized steel DC56D in an overlap configuration is carried out. The effect of the welding speed on penetration depth and tensile shear strength of the joints are studied experimentally. On the other hand, the comparison of the joint strength of the single-weld and that of double-weld assemblies is investigated. The microstructure of the joint and the chemical composition of the intermetallic compounds and the fracture of the tensile specimen are investigated by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) separately. The results indicate that the joint tensile shear strength is great with limiting the penetration depth under appropriate welding speed. The kinds of the intermetallic layer are Fe2Al5, FeAl2 and FeAl3. The double-weld assembly is contributed to improve the joint strength, and the maximum tensile shear strength is 155 N/mm, about 84% of that of the aluminum substrate, which is 26% higher than that of single-weld assembly. In tensile test, the specimen fracture is in heat-affected zone or substrate of aluminum, and the fracture form of the joint is ductile fracture.